Implantable medical devices (IMDs) can perform a variety of diagnostic or therapeutic functions. In an example, an IMD can include one or more cardiac function management features, such as to monitor the heart or to provide electrical stimulation to a heart or to the nervous system. The cardiac function management features can be used to diagnose or treat a subject, for example, in cases of electrical or mechanical abnormalities of the heart. Examples of IMDs can include pacers, automatic implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy (CRT) devices, implantable monitors, neuromodulation devices (e.g., deep brain stimulators, or other neural stimulators), cochlear implants, or drug pumps, among other examples.
Such IMDs can include a housing carrying electronic circuitry configured to wirelessly transfer information between implanted IMDs, or between an IMD and an assembly external to the body. Such information can include, for example, programming instructions or configuration information to configure the IMD to monitor, diagnose, or treat a physiologic condition. Such information can also include data sensed, detected, or processed by the IMD and transmitted to another device or assembly (e.g., physiologic information, a disease status, etc.). Electrodes can be connected to the housing via a connective part referred to as a header. The header and the leads have largely been standardized. The header can include a relatively deep female socket (e.g., a bore) having a number of contact surfaces whereas the lead can be provided with a male part comprising one or several corresponding peripheral, generally circular contact surfaces. Each lead has a designated bore, and inserting a lead into an incorrect bore of the header can cause malfunctions of the IMD after implantation.
The leads are electrically connected to the electronic circuitry of the housing via one or more contact wires extending from the housing. The number of contact wires can vary and as the number of contact wire increases, the risk of wire crossing can also increase. Incorrect connection of leads into the bores and wire crossing can cause various errors such as the stimulation or sensing of the wrong chambers of the heart, incomplete or intermittent connectivity between leads and the IMD, or ineffective defibrillation therapy. Correcting the errors can result in extended procedure durations. In some cases, correcting the errors can require subsequent surgical revisions, thereby increasing the patient's risk of morbidity and mortality.